docs: def mouseDown(self, button):
          """ Send a mouse button down at the last set position
  
              button: int: [1-n]
  
          """
          log.debug('mouseDown %s', button)
          self.buttons |= 1 << (button - 1)
          self.pointerEvent(self.x, self.y, buttonmask=self.buttons)
  
          return self